When firing fireworks the pyrotechnic launcher tubes, also called mortars, are known and consist in a cylindrical body closed on the bottom, which houses inside both the objects or pyrotechnic materials, such as the shell or fountains, and the projection load, also called lifting propellant. Any pyrotechnic component housed inside the mortar is projected outwards to produce a visual and/or audible effect by means of the gases generated by the combustion of the projection load. The projection of one or another type of pyrotechnic material is produced in different ways, causing a different effect.
For the purpose of aiding the understanding of the present document and given the particular terminology used in some of the different prior art that will be cited below, it is considered particularly important to clarify the following concepts:
Conventionally and in general terms, a shell is a pyrotechnic device that is structured with a plastic or cardboard casing, having a geometric cylindrical or spherical shape, that contains a projection load which is ignited through an ignition conduit by means of a squib or fuse, generating gases whose thrust, channeled though a pyrotechnic launch tube, projects the shell upwards, emerging to the exterior of the pyrotechnic launching tube. The delay in the transmission of lighting of the shell is produced by the operation of a delayed fuse that is ignited by the projection load; this burns during the launch of the shell and ignites the explosive load located inside the casing when the shell reaches its zenith, provoking the brusque and instantaneous opening of the box, propelling and lighting the pyrotechnic materials that will create the desired effect at a great height.
Conventionally a fountain is a device having a operating principle that is similar to that described for the shells, with the exception that this does not have a delay fuse and is designed so that the casing holding the pyrotechnic components remains inside the mortar in the moment it is fired, opening the top portion of said casing enabling the components to produce their visual and audible effect, by means of the emission of flashes of light that emerge from the mouth of the mortar at a reduced height.
Customarily, both the shells and the fountains are devices designed to be fired from inside an appropriate mortar for their calibre.
The assembly resulting from the manufacturing process having one or several of these devices inside a single cylindrical mortar, fixing its load to the internal mortar wall by means of internal retention elements such as sealing washers or similar, is called a Roman candle. Therefore, a Roman candle is understood to be the device shaped by a cylindrical tube, generally cardboard or plastic, that fires one or several objects or pyrotechnic materials housed inside it, these being any type, such as a fountain type, shell (or mini-shell) and kite, which, with the possibility of the cooperation of an intermediate screen, are separated from the projection load, said tube being closed at its top end by means of a top cover, the cylindrical tube having the ability to be fixed, for example, to a frame or including a flange that enables its support, in which the Roman candle tube forms part of the device itself.
Said Roman candles have a mortar in their structural assembly, inside of which the pyrotechnic components are housed. These remain immobilized inside the cylindrical tube, fixed by retaining gaskets or any other element that can carry out this mission. This type of retaining system, which is always located on top of the pyrotechnic components, is the conventional and common system employed for manufacturing the Roman candles.
The use of the cited devices, namely, shells, fountains and Roman candles, has several drawbacks.                It entails a technical disadvantage because those firings in which the mortar must have some inclination, a shifting occurs of the pyrotechnic load inside it when being put in place. To avoid these movements, retaining elements are usually used on top of the load, such as locking discs, which actuate by putting pressure on the inside wall of the mortar, avoiding movement of the load and cooperating to exercise sufficient compression so that the pyrotechnic materials are lifted up the necessary height. These elements are unavoidably ejected outside, pushed by the device itself, creating an inconvenient increase of residues and hazards if the devices are close to the public. There are retaining elements that burn before being ejected from the mortar, but these are very expensive and not common in conventional use.        Furthermore, all of the pyrotechnic components have to be deployed inside a cylindrical mortar, permanently closed on the bottom face by glue, staples, screws or threads with respect of a bottom base, for which the loading operation always needs to be carried out through the top portion of the mortar. This entails the need to lengthen the ignition means, either a fuse or an electric igniter, extracting it from the top portion of the mortar itself, or through an orifice made in the side of the mortar.        
In the case of Roman candles, we are faced with additional drawbacks.                In these types of devices the projection load is conventionally deployed inside the mortar, without using any type of container. The pyrotechnic components are deployed on top of it. In this way, the mortar itself, which forms part of the structural assembly of the devices, is what actuates as a type of recipient for housing the lifting or projection load. This leads to the consequence that the combustion of the mortar deteriorates it, complicating its subsequent reuse.        
The invention at hand tries to resolve the aforesaid drawbacks so that:                The pyrotechnic load is isolated inside the mortar in a safe and sealed manner.        Subsequent use of the mortar is made possible for new firings, as it does not become deteriorated.        The separation of unnecessary structural elements is avoided, obtaining greater safety during the fireworks show, because it does not require any additional locking element, thus avoiding it being propelled outside and eliminating the danger of it falling among the public and subsequent clean up tasks.        It assures the pyrotechnic materials are fixed inside the pyrotechnic tube and guarantees a better contact of an electric igniter located inside the device and a locking element.        The fact that the pyrotechnic load may be introduced from either the bottom or the top portion of the mortar, makes it possible to include in the design of the device non-detachable locking means that cooperate with the internal face of the mortar, avoid shifting during assembly, improve the safety system and make its installation easier.        It improves the compression of the gases during combustion without the need of using detachable locking elements on top of the pyrotechnic materials.        
Conventionally, mortar is understood to mean a tube that is used to project pyrotechnic components, and so it constitutes a separate piece from the device.
The applicant hereof holds Spanish Patent ES 2287458, consisting in a locking system for non-reusable pyrotechnic launch tubes, specifically for those that consist in the pyrotechnic launch tubes themselves, equipped with a cylindrical body housing inside it both the objects or pyrotechnic materials and the lifting propellent, which is characterized in that said tube is equipped on its bottom end with a plurality of tabs which, as a set, configure a cylindrical, radial and elastically deformable neck, in which said tabs terminate on respective locking barbs on top of a locking piece, fixable to the frame of the tubes or integrated onto this frame to form a single piece. Furthermore, the pyrotechnic launch tube is adapted for housing an igniter inside it with its corresponding feeder cable; however, this launch tube has a small opening on its bottom portion which is not equipped for introducing a pyrotechnic device through it; rather it is only for housing said igniter. This makes it necessary to perforate the base of the launch tube by making an orifice for said housing, which may complicate maintaining its airtightness, resulting in the entry or filtration of gases during ignition and even the need of placing the igniter before the lifting propellent so as to keep the propellent from falling out of said orifice.
The intervention at hand further tries to improve different features of the frame itself, such as the locking system between it and the pyrotechnic launch tubes, being now reusable and exchangeable, with anchoring devices that provide greater safety to the assembly and a considerable increase in reliability, as well as the introduction and installation of a pyrotechnic device both through the bottom portion and the top portion of the pyrotechnic launch tubes, unlike the state of the art.